/*
 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package java.security;

import java.util.*;
import java.io.ObjectStreamField;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;

/**
 * A UnresolvedPermissionCollection stores a collection
 * of UnresolvedPermission permissions.
 *
 * @author Roland Schemers
 * @serial include
 * @see java.security.Permission
 * @see java.security.Permissions
 * @see java.security.UnresolvedPermission
 */

final class UnresolvedPermissionCollection
    extends PermissionCollection
    implements java.io.Serializable {

  /**
   * Key is permission type, value is a list of the UnresolvedPermissions
   * of the same type.
   * Not serialized; see serialization section at end of class.
   */
  private transient Map<String, List<UnresolvedPermission>> perms;

  /**
   * Create an empty UnresolvedPermissionCollection object.
   */
  public UnresolvedPermissionCollection() {
    perms = new HashMap<String, List<UnresolvedPermission>>(11);
  }

  /**
   * Adds a permission to this UnresolvedPermissionCollection.
   * The key for the hash is the unresolved permission's type (class) name.
   *
   * @param permission the Permission object to add.
   */

  public void add(Permission permission) {
    if (!(permission instanceof UnresolvedPermission)) {
      throw new IllegalArgumentException("invalid permission: " +
          permission);
    }
    UnresolvedPermission up = (UnresolvedPermission) permission;

    List<UnresolvedPermission> v;
    synchronized (this) {
      v = perms.get(up.getName());
      if (v == null) {
        v = new ArrayList<UnresolvedPermission>();
        perms.put(up.getName(), v);
      }
    }
    synchronized (v) {
      v.add(up);
    }
  }

  /**
   * get any unresolved permissions of the same type as p,
   * and return the List containing them.
   */
  List<UnresolvedPermission> getUnresolvedPermissions(Permission p) {
    synchronized (this) {
      return perms.get(p.getClass().getName());
    }
  }

  /**
   * always returns false for unresolved permissions
   */
  public boolean implies(Permission permission) {
    return false;
  }

  /**
   * Returns an enumeration of all the UnresolvedPermission lists in the
   * container.
   *
   * @return an enumeration of all the UnresolvedPermission objects.
   */

  public Enumeration<Permission> elements() {
    List<Permission> results =
        new ArrayList<>(); // where results are stored

    // Get iterator of Map values (which are lists of permissions)
    synchronized (this) {
      for (List<UnresolvedPermission> l : perms.values()) {
        synchronized (l) {
          results.addAll(l);
        }
      }
    }

    return Collections.enumeration(results);
  }

  private static final long serialVersionUID = -7176153071733132400L;

  // Need to maintain serialization interoperability with earlier releases,
  // which had the serializable field:
  // private Hashtable permissions; // keyed on type

  /**
   * @serialField permissions java.util.Hashtable A table of the UnresolvedPermissions keyed on
   * type, value is Vector of permissions
   */
  private static final ObjectStreamField[] serialPersistentFields = {
      new ObjectStreamField("permissions", Hashtable.class),
  };

  /**
   * @serialData Default field.
   */
    /*
     * Writes the contents of the perms field out as a Hashtable
     * in which the values are Vectors for
     * serialization compatibility with earlier releases.
     */
  private void writeObject(ObjectOutputStream out) throws IOException {
    // Don't call out.defaultWriteObject()

    // Copy perms into a Hashtable
    Hashtable<String, Vector<UnresolvedPermission>> permissions =
        new Hashtable<>(perms.size() * 2);

    // Convert each entry (List) into a Vector
    synchronized (this) {
      Set<Map.Entry<String, List<UnresolvedPermission>>> set = perms.entrySet();
      for (Map.Entry<String, List<UnresolvedPermission>> e : set) {
        // Convert list into Vector
        List<UnresolvedPermission> list = e.getValue();
        Vector<UnresolvedPermission> vec = new Vector<>(list.size());
        synchronized (list) {
          vec.addAll(list);
        }

        // Add to Hashtable being serialized
        permissions.put(e.getKey(), vec);
      }
    }

    // Write out serializable fields
    ObjectOutputStream.PutField pfields = out.putFields();
    pfields.put("permissions", permissions);
    out.writeFields();
  }

  /*
   * Reads in a Hashtable in which the values are Vectors of
   * UnresolvedPermissions and saves them in the perms field.
   */
  private void readObject(ObjectInputStream in) throws IOException,
      ClassNotFoundException {
    // Don't call defaultReadObject()

    // Read in serialized fields
    ObjectInputStream.GetField gfields = in.readFields();

    // Get permissions
    @SuppressWarnings("unchecked")
    // writeObject writes a Hashtable<String, Vector<UnresolvedPermission>>
        // for the permissions key, so this cast is safe, unless the data is corrupt.
        Hashtable<String, Vector<UnresolvedPermission>> permissions =
        (Hashtable<String, Vector<UnresolvedPermission>>)
            gfields.get("permissions", null);
    perms = new HashMap<String, List<UnresolvedPermission>>(permissions.size() * 2);

    // Convert each entry (Vector) into a List
    Set<Map.Entry<String, Vector<UnresolvedPermission>>> set = permissions.entrySet();
    for (Map.Entry<String, Vector<UnresolvedPermission>> e : set) {
      // Convert Vector into ArrayList
      Vector<UnresolvedPermission> vec = e.getValue();
      List<UnresolvedPermission> list = new ArrayList<>(vec.size());
      list.addAll(vec);

      // Add to Hashtable being serialized
      perms.put(e.getKey(), list);
    }
  }
}
